Drilling apparatus



March 21, 1950 J. c. CURTIS DRILLING APPARATUS 5 Sheets-Sheet l Filed NOV. l5, 1944 @u n r d l w @n uw uw www. %\\Q|- w.. O T Nm nv@ L ||..||l| l f lwmw .1. m W QW \-O W Q W Ns HHHH||| I b Nw MIIIIHr/ G O v ,Y m bv m%.\ w om. 1 Hb \Mr|| U Nw ww S m Qw E w n, Ww h mw .Nw N s March 2l, 1950 J. C. CURTIS DRILLING APPARATUS SSheets-Sheet 2` Filed Nov. l5, 1944 March 2l, 1950 J. c. CUR-ris 2,500,931

^ DRxLLING APPARATUS Filed Nov. 145, 1944 5 Sheets-Sheet 5 [Umb lillnl :klim A I 05 [an mi 2 62 4 mil, IAM 6 6/ n /2 'L hq 6% gf 4 L j Y 6 `dh (9@ gd/ 6 March 2l, 1950 J. c. CURTIS 2,500,931

DRILLING APPARATUS Filed Nov. 15, 1944 v5 sheets-sheet 4 d Izzi/faxing):

I l MAW/14am V 3? wfg March 2l, 1950 J. c. cuRTls DRILLING APPARATUS Filed Nov. l5, 1944 5 Sheets-Sheet 5 Patented Mar. 21, 1950 NITED STATES PATENT OFFICE.

Pennsylvania .Application November 15, 1944, Serial No.` 563,579

15 Claims. l

This linvention relates to drilling apparatus and more particularly to an improved Iportable supporting structure fora `rock drill, especially designed for use in .tunnel Work for supporting the rock drill in various positions with respect to thetunnel face.

In a lportable rock Ydrill such as is employed in tunnel work, there is usually yprovided an adj-ustable support for supporting the drill inthe desired position with'respect to the face of the tunnel. Such supporting apparatus is commonly known as a rock Adrill jumbo and usually embodies adjustable armlike vsupports by each of which a drill is supported. In vsuch apparatus it is desirable rigidly vto hold thesame in position between the -tunnel roof and floor during the drilling operation. It is also desirable that the apparatus may be `readily moved as the tunnel face advances and may be quickly'and easily adjusted into the desired supporting position. In such apparatus it is also a desired feature to enable location of the rock drill relatively close to the tunnel walls and the roof and floor of the tunnel. When the vapparatus is kheld in drill supporting position stability and comparative freedom from vibration are necessities. Also `the laborious task vof manually lifting relatively heavy parts into the desired kposition must be avoided.

It is an object of thepresent invention to provide an improved portable drill supporting apparatus of the type commonly known as a'iock drill jumbo Another object is to provide an improved drill supporting apparatus having improved means for adjustably supporting a 'rock drill with respect'to the work. A further object is to provide an improved rock drill jumbo especially designed for use in tunnel work having improved means for rigidly securing the same with respect to the working 'face of the tunnel during the drilling operation. Still another object is to provide an improved wheeled support for a rock drill radapted to run along a trackway and having novel means engageable with the roof for locking the truck wheels in 'a stationary position with respect'to the Atrackway. A still further object is to provide improved means engageable with the roof Afor effecting braking of the wheels rigidly to hold the same 'in position on the trackway. .A still further object is to provide an vimproved adjustable drill supporting apparatus embodying a swivelled boom frame on which a rock drill is universally mounted in a novel manner, whereby the drill may be located relatively close "to the tunnel yside 'walls land the roof and door vother object is to provide lan improved adjustof 'the tunnel. Yet anable boom frame structure embodying improved means for locking th'esa'me in adjusted position. vStill another object is to provide an improved wheel braking system operated bythe roof engaging'jack, 'for holdingjthe truck of the apparatus in 'a stationary vpositionon the track rails. 'A `further object-is to provide an improved 'swiv- -el mounting structure for the 'rock'drill yat the uouter extremity `of the adjustable l supporting boom ofthe apparatus. These'andother objects and advantages of lthe invention will, however, lhereinafter more fully appear.

In the-'accompanying drawings there are shown Ifor purposes of illustration one vform 'and two "modifications which the invention may assume in practice.

In these drawings:

Fig. A1 'is a plan View 'of a drilling apparatus constructed in accordance with an illustrative .tical 'section taken substantially on line 1-1 of Fig. 1.

Fig. vv8 is ank enlarged longitudinal sectional View vtaken substantially on line 8-8 of Fig. 1.

Fig. 9 is lan enlarged cross-sectional view taken online 9-9 of Fig. 8.

Fig. l0 is an enlarged horizontal sectional View taken substantially on line lll-l0 of Fig. 2.

Fig. 1l is a fragmentary side elevational view showing a modiiied construction.

Fig. 12 is a -side elevational View on .a reduced scale illustrating lanother modified construction.

In the illustrative embodiment'of the invention the improved drilling apparatus is of the type .known as a rock drill jumbo 4especially Yclesigned Yfor use in tunnel work, and embodies an improved portable supporting structure for a rock drill for supporting the latter at various vlocations with respect to the working face of the tunnel. It will be evident, however, that the features of the inventionumay be embodied in .other types -of apparatus.

The improved drilling apparatus or so-called rock drill jumbo, as shown in Figs. 1 and 2, comprises a portable base I desirably in the form of a truck frame 2 mounted on wheels 5 adapted to travel along the rails of a trackway laid on the tunnel floor. The jumbo disclosed herein is of the twin or dual drill type, although if desired, but a single or more than two drills may be used. Carried by the truck frame at its forward portion is a pair of swivel frames or turntables 5 mounted to turn about parallel upright axes at opposite sides of the longitudinal vertical center oi the base. Pivotally mounted on these swivel frames or turntables to swing in a vertical direction relative thereto are elongated supports or boom frames E respectively in turn having swivelly mounted at their outer ends rock drills l of the conventional mounted drifter type. By adjusting the boom frames horizontally about the swivel frame axes and vertically about their pivots relative to the swivel frames, the rock drills may be located at any desired position with respect to the tunnel face.

The truck frame 2 has secured thereto a stationary rear axle 8 for the rear wheels and a iront axle 9 for the front wheels, mounted in vertical guides I9 secured to the truck frame (Figs. 3, 4 and 7 Arranged between the bottom of the truck frame and the front axle are coil springs II arranged in recesses I2. Thus a yieldable front axle mounting is afforded for the truck. In the modication shown in Fig. 1l a rear axle I3 is mounted in similar guides Ill and similar springs I4 are arranged between the bottom of the truck frame and the axle so that yieldable i mountings are provided for both axles. 'Ihe purpose of the yieldable axle mounting will later be explained.

Carried on the truck frame rearwardly of the swivelledboom supporting frames 5 at the loninder contains a reciprocable piston I9 having a tubular piston rod 29 extending upwardly through the packed top head 2I of the cylinder. Received in the hollow piston rod is a pointer bar 22 having a shoulder abutting the upper end of the piston rod and terminating at its upper end in the point 23 engageable with an extraneous abutment such as the tunnel roof. When the jack mechanism is swung downwardly about its pivotal mounting on the cross bar I8, the pointer bar may be withdrawn from the piston rod to reduce the overall height of the apparatus dur ing transport. The swivelled boom supporting frames 5 are mounted on a horizontal cross plate 24 secured as by welding to the sides of vthe truck frame, and on this cross plate is a rearward apertured lug 25 (Fig. '7) for limiting upward swing of the jack mechanism I5 and to lock the latter in a substantial upright position. The base of the jack cylinder has spaced apertured lugs 26 between which the lug 25 is receivable, and a pin 2'! is receivable in the registering lug apertures for securing the jack mechanism in upright position. When the pin is released, the jack mechanism may be swung downwardly on the cross bar I8 to permit removal of the pointer bar as above mentioned. If desired, during transport, the jack mechanism may be laid down on the truck in an out-of-the-way position in an obvious manner. Embodied in the jack cylinder base is a liquid reservoir 28 and a conventional pump 29 operated by a hand lever 39 so that liquid may be manually pumped through the conduit 3i into the jack cylinder IS below the piston I9 to move the latter upwardly to adjust the bar point 23 into engagement with the tunnel roof. A valve mechanism 32 is associated with the pump for controlling ow of liquid to or to trap fluid in the jack cylinder and is positionable to connect the conduit BI to the reservoir so that liquid may be discharged from the jack cylinder to eiect lowering of the pointer bar. When the jack mechanism is operated and a suitable pressure is applied to the truck frame, the latter is swung downwardly about the rear wheel axes thereby compressing the springs of the front axle to bring brake shoes 33 on the truck frame into braking engagement with the treads of the front wheels so that the truck is held in a stationary position on the trackway, in the manner disclosed and claimed in my copending application Ser. No. 38,045, filed July 10, 1948. In the modification shown in Fig. 12, a jack mechanism 34 is arranged approximately in a transverse vertical plane which includes the front wheel axes so that the jacking pressures are applied directly through the front wheels to the trackway thereby rigidly to hold the apparatus in position between the tunnel roof and floor in a manner functionally simulating a conventional mine column. In the modication shown in Fig. 11 brake shoes 35 secured to the truck frame engage the treads of the rear wheels so that all four wheels are braked when the jack mechanism is operated.

The horizontal plate 24 for the swivelled boom supporting frames 5 has attached thereto by screws 31, the bottom flanges (Fig. 3) of a pair of tubular pedestals 38 on which cylindrical portions 39 of the swivel frames 5 are respectively rotatably mounted` The rear ends of the boom frames 6 are pivoted at 49 on the swivel frames 5 respectively to swing in a vertical direction with respect thereto. There are locks for holding the swivel frames 5 against rotation with respect to the stationary pedestals comprising tapered surfaces 4I (Fig. 3) on the lower portions of the pedestals with which conical surfaces 42 on the swivel frames are engageable. The operating means for the locks may assume various forms but are herein, for illustrative purposes, shown similar to those disclosed and claimed in a copending joint application of Curtis and Gartin, Serial No. 566,056, led December 1, 1944. Arranged centrally within the pedestals and secured thereto at 43 are screw shafts 44 on the upper ends of which are threaded hand nuts 45. These hand nuts engage the top surfaces of the swivelled boom supporting frames 5, and, when the nuts are turned in the proper direction, the boom supporting frames are moved downwardly to force the conical surfaces thereon into frictional locking engagement with the stationary conical portions 4I.

Fluid operated jacks are desirably employed to swing the boom frames about their pivots, these comprising hydraulic cylinders 46 (Fig. 8) pivotally connected at 4I to the swivelled boom frames 5 at points below the boom pivots 40. Reciproeable in these cylinders are 'pistons 48 each having its piston rod 49 engaging at 50 the :outer end of a1; tubulars sleeves5 l whichaencloscs zand lhas telescopic r relation with-ther feedf; cylin- 53. Byctighteninggthe:clamp bolts, ,thesleeves y and the cylinders arelockedgtogether to-holdthe boom frames in adjusted position aabout their pivots.

-Carried by eachof-thefswivelledoboom :Slipporting frames-5 isa liquidreservoir ,.55 (Fig. l0.) and a conventionalf purrrp-- 56 Aoperatedibhta. hand lever 5l. The. pump'has.its;'dischargefconnected 4Voy-a conduit A58'to vthe vinnerf'end .ofpthe cylinder 46, and 'valve means 59 1 is associated Withpthe jpump for connecting the-ffconduit- 58 back f toqthe reservoirso that liquid :can bei dischargedfrom lthe cylinden -By manually :operating '",the pumpsfthe hydraulic jacks, may be operatedto lift the boom frames, l-a1f1,d,= bydischargingfliquid from the lower ends-of thecylinders, theiboom frames may-be lowered. aWhen theya-lvelmeans SSV-is closed liquid -may betrapped in ,thezjaok cylinders.

Now referringto the Vimproved universal swivel mountings forthcirock drillsfat the louter exf tremities of the-boom frames, it `iwillbe noted that mounted on Vthel outerfendof each boom frame: toV turnfabout the. longitudinal axis. `ofi the boom frame isa rotatable ysupportlill (Fi-g. 5)

held in adjusted vpositionbya split'olamp lvhavling an adjusting bolt 62. -Arrangedinlthe -ro tata-ble support` lill-in' advance :of the Iboom frame .is a conical socket-.63 for receiving vthe ztapered portion 64' of. a lateral-arm .65. :An adjusting device in the form ofa bolt-65 isfprovidedforgsecuring the 4tapered portion Edtig-htly withintthe vsocket to lock the arm-65 inv position, and, when this bolt is released, the lateralarm'65 maycbe turned relative Vto the support-fabout anaxis at right .angles to the longitudinal axis of `the boom frame. .The locking'means forfthe arms 65may assume variousforms but, as herein :de scribed, theyare for illustrative purposes-,shown similar to those 'described in claims .in the joint Curtis and Gartin application lmentioned above. Formed in .the arm. is a.socket-61.-(Eig..6) yfor receiving a circular swivelvplate on a support B9. The arm 65 has an opening.10,andfthefarm beneath the.V socket has a guideway H which enters the opening'lll. Arranged in this-guideway and heldagainst rotation rtherein lisa zclarnp 'I2 for enga-ging theswivel plate..68. When-.this clamp is tightened byits adjusting bolt-'13,` the swivelplate is secured in `its adjustedyposition.

When released, the swivel .plate mayberturned relative to the .arm 65 .about'an axisfat right angles to both the arm axis Aandthe longitudinal axis of the boom frame. The swivel support -69 has gu-ideways 'M for slidably receivingvflanges 15 formed on a guide shell 76. Theguide .shell may be slid longitudinallyin the iguideways of the support 69, and-a clampI 'l1 adjusted by-a bolt 18 may `be tightened to clampl theguide shelLin adjusted position. The guide. shell has longitudinal guideways 19 for receiving guidesf onthe motor cylinder 8| of the rock drill ,'l. Reciprocable in the motor cylinders of therock drillsfare hammer pistons (not shown) for, striking-blows on usual drill steelsl 82, the latter :suitably .supported within the rock drill chucks. Each rock drill has a feedmotor-83rfor rotating `a usual feed screw-84 for feeding the rock drills `back and forth along` the shellvguideways. z Each rock drill is. ofk a well-known designandmayzbeggenerally similar. to thatdisclosed ing-my-.Patent'No 2,320,511, 1patentedl,;-Jnne 1, 19.13. Qf' .frcoursa other rock drills of thermounted-Ldrifter :or-fairly other l.suitable type may ymbe used :with-:my improved jumbof-fzdesired.

The rockf-,pdrills 'hand-the drill :feedemotors l83 are; operatedeby pressurve;l uidwhich is f supplied tothe apparatusthrough.a-.supply.hoser85 on `vthe truck framecaconncctedtoxaxmanifold 86. ,Leading from thefmanifolmare 1l-uid Iconductinghoses rs1 connected f .toz constant' pressure chambers 588 inithe boomfr'amesf'respectively (Fig..8) .'Leadking fromqthe boomt framey chambers :788, through .line oilers 11 8,9 lare hoses 1 90 .connected to throttle valve mechanisms r9 Lof thee rock drills. Branch hoseconnectionsf-92are connected tothe intakes of the feed motors 83'; .;under .the control Jof?` valve mechanisms-9,3.

T-he general mode of.y operationof the improved drilling apparatus is .if as f follows. .The .apparatus may be moved ,alongathe yftrackwayfin; anyv suita- :ble-.mannerzand Whenlocatedat they tunnel face,

lthe jackmechanismlB may befswung into :up-

right position and lockedwtherein. The operator may then vosci'llatetl'le hand lever 30 ofithepu-mp v29 to force :liquidunder pressurefrorn the reservoirf through. conduit 3-| tothelower :endof the jack cylinder |-6 :to `move ythe,.1: istonj I'9 upwardly .thereby raising;V the point .23 `of :the pointer bar into vcontactwith the-tunnel'roof. fAsgthe,y pointer loan-is` forced into-contactwith the roof, the truck frame f2 1 is -sw-ung downwardly rcompressing vthe springs to bring the brake shoes :i3-*into engagement with .the .front-,wheel treadsx-to Ybrakel the wheels and to hold rigidly the 1wheelsfin engagement with therailsofthe.trackway. 4'Fhe'liquid may bevtrapped @in f the I jack. Vcylinder iunder the l control of the fvalve 'mechanism 132 to hold `,the jack mechanism@ in ,this position. .The Yoperator Imay then oscillate the-'hand'levere51- of; the pump 56 to force.' liquid gvunder; pressure from the reser- .voirfthrough `:thezconduit :58 toy the` inner .end .of the hydraulic `liftingrcylinder 45:1;0 move the piston :48 outwardly; thereby; toreffect raising 'of' the vboomframe. :The boom framefmayzbe lowered by'dischargingpliquid from'the hydraulic lifting cylinder backto v:the reservoir= under control of the Vvalve mechanisnr'59. vVl/'herrthe-'boom'frames rare'in the desired-'adjustedfpositionthev clamps 52, 53 may be tightened to lock the sleevesfl and vcylinders 46 together to hold firmly the .booms in position. v-By loosening the friction locks14|,f4 2, 'Mfor the swivelled lboorn supporting framesl, the boom frames maybe'fswung laterally into the :desired position v'about the yupright yaxes and thereafter firmly locked rin position. By adjusting the severalclampsythe drill -guide shell 16 may be adjusted intothe desired positionatf'the outer end of the boom frame, and,` by tightening these clamps,'the jguide shellmay Ibe rigidly-held in ,adjustedposition lBy loosening the clamps 6|,.62 for the rotatablesupports 60, thedr`ills maybe radjusted relative to the boom frames uabout the `longitudinalaxes of 'the boomframes, and, by looseningthe'clamps v(i3, '64, B5, thedrills may' be swung; about" axes Vat "right angles tothe longitudinal `axes of jthe boom frames. Fluid under'pressure may be supplied throughthe `hose .connections 31, 90, and 92,to the `motors ofthe drills "land thefeeding motors 83 undercontrol `of thevalve mechanisms 9|,.andf93. .In the vmodifcation shown in Eig. ,11, allfour. wheels .of the truck vare braked-and held .stationary withrespect to the.l trackway, ,-.and in ,the vmodicatim .shownin vEiga 12,v tha `jack,,mechanism `Miemplies the clamping pressure directly through the front wheels to the trackway.

As a result of this invention, an improved drilling apparatus of the type known as a rock drill jumbo especially designed for use in tunnel work, is provided in which desirable improvements are incorporated resulting in improved operation. The apparatus may be held rigidly in position between the tunnel roof and iioor during the drilling operationand the same may be expeditiously moved from place to place. By the provision of the horizontally and vertically swingable boom frames and the improved swivel mountings-at the outer extremities of the boom frames, the rock drills may be adjusted into any desired position with respect to the face of the tunnel. The novel locks for the boom supporting and boom frames enable nrm holding of the boom frames in their adjusted position and the locks may be quickly released when desired. These and other uses and advantages of the improved drilling apparatus will be clearly apparent to those skilled in the art.

While there are in this application specifically described one form and two modifications which the invention may assume in practice, it will be understood that this form and two modiiications of the same are shown for purposes of illustration and the invention may be further modied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

1 What I claim as new and desire to secure by Letters Patent is:

1. In a drilling apparatus, a support having a pedestal thereon, a drill supporting frame having a bore receiving said pedestal with an upper portion of said frame closing said bore above said pedestal, means for mounting said frame on said pedestal to turn relative thereto and to slide a limited amount longitudinally thereof, and means for locking said frame against turning movement relative to said pedestal including cooperating locking elements on said frame and pedestal, and adjusting means engaging said upper frame portion above said pedestal for sliding said frame axially downwardly relative to said pedestal to bring said locking elements into coaoting locking engagement.

2. In a drilling apparatus, a support having a y pedestal thereon, a drill supporting frame having a bore receiving said pedestal with an upper portion of said frame closing said bore above said pedestal, means for mounting said frame on said pedestal to turn relative thereto and to slide a limited amount longitudinally thereof, means for looking said frame against turning movement relative to said pedestal including cooperating locking elements on said frame and pedestal, and adjusting means engaging said upper frame portion above said pedestal for sliding said frame axially downwardly relative to said pedestal to bring said locking elements into coacting locking engagement, said adjusting means arranged coaxially with said pedestal and including a rotatable adjusting element engaging said upper frame portion, and coacting means secured to said pedestal.

3. In a drilling apparatus, a support, a drill supporting frame pivotally mounted on said support to swing relative thereto, and an extensible power device extending between said support and said frame for swinging the latter including relatively reciprocable power operated elements, a tubular member surrounding one of said elements 4ciprocable piston operatively connected to said frame, a tubular member surrounding said cylinder in telescopic relation therewith and arranged to move with said piston relative to said cylinder, and a clamping device for securing said tubular member and said cylinder together to lock said piston in adjusted position.

5. In a drilling apparatus, an armlike member having an outer end portion formed with an open center and a guideway extending lengthwise of said member within the open center of said end portion, said member having a socket for receiving a swivel plate of a drill support, and a clamp guided in said guideway for outward rectlinear movement and projecting into said open center into clamping engagement with the swivel plate.

6. In a drilling apparatus, a base, aboom frame pivotally mounted on said base to swing in a vertical direction relative thereto and adapted to support a drill at its outer extremity, a fluid operated device for swinging said boom frame upwardly about its pivot and for permitting controlled lowering of said boom frame by gravity including relatively reciprocable fluid operated elements, and associated clamping means for locking said elements against relative movement to hold said boom frame in adjusted position irrespective of the fluid in said device including a tubular clamp-carrying element coaxial with said `device and housing one of said elements and reciprocably receiving said other element, and means on said tubular element and engageable with said element reciprocably received therein for clamping the parts against movement.

7. In a drilling apparatus, a base frame having an upstanding pedestal thereon, a drill supporting frame swivelly mounted on and surrounding said pedestal and having limited movement longitudinally thereof, and means for locking said frame against movement on its swivel mounting on said pedestal including a conical locking portion on the base of said pedestal, a conical locking surface on the lower portion of said frame, and means engaging said frame and said pedestal for movingr said frame longitudinally of said pedestal in a downward direction to bring said conical surface into frictional locking engagement with said conical portion.

8. In a drilling apparatus, an armlike member having an outer end portion formed with an open center and a guideway extending transversely partially across the open center of said end portion, said member having a socket for receiving a swivel plate of a drill support and opening laterally at its inner side toward said open center so that one side of the swivel plate is exposed, and a clamp guided in said guideway and projecting into said open center at the open side of said socket and adjustable into clamping engagement with the exposed side of the swivel plate.

9. In a drilling apparatus, a base, a boom frame pivotally mounted on said base to swing in a vertical direction relative thereto and adapted to vperiphery of said cylinder element to lock the parts in position.

10. In a drilling apparatus, a base having a pedestal thereon, said pedestal having a iree upper end, a drill supporting frame having a bore receiving said pedestal, said frame having an upper portion closing the upper end ci said bore above said pedestal, means for swivelly mounting said frame on said pedestal to turn horizontally relative thereto about the longitudinal axis of said pedestal, said mounting means permitting limited sliding movement ci said frame axially relative to said pedestal, a lock for holding said frame against turning movement on its swivel mounting including coasting locking elements one rotatable with said frame and the other stationary with respect to said pedestal, and an adjusting device arranged coaxial with said swivel and engaging said upper frame portion for sliding said frame axially relative to said pedestal to bring said locking elements into ooacting locking relation.

11. In a drilling apparatus, a portable base, a drill supporting frame swivelly mounted on said base to swing laterally and upwardly relative thereto, a jack device engageable with an eX- traneous abutment for securing said base in a stationary position during the drilling operation, uid operated means for swinging said drill supporting frame in one of aforesaid directions on its swivel mounting, and fluid operated means for extending said jack device, each of said fluid .f

operated means including a duid reservoir, one reservoir on said frame and the other on said jack device, and a pump associated with veach of said reservoirs, each pump having its intake connected with a reservoir and its discharge i connected to a fluid operated means.

12. In a drilling apparatus, a portable base, a pair of pedestals mounted on said base near its forward end and spaced equidistantly from the longitudinal vertical center of said base, frames swivelly mounted on said pedestals respectively to turn horizontally relative thereto, boom frames pivotally mounted on said swivel frames respectively to swing in a vertical direction relative thereto and each adapted to carry a drill at its outer extremity, iiuid operated means for independently swinging said boom frames in a vertical direction about their pivots, a jack device arranged with its longitudinal axis lying in the central longitudinal vertical plane of said base and engageable with an extraneous abutment for securing said base in a stationary position during the drilling operation, and fluid operated means for extending said jack device, and means for supplying uid under pressure individually to said uid operated means including uid reservoirs, one mounted on said jack device and others mounted one on each of said swiveled frames, and a pump associated with each fluid reservoir, each pump having its intake connected to a reservoir and its dischargeconnected to a fluid operated means.

1,3. lIn a drilling apparatus, an armlike member having an outer end portion formed with an open center and a guideway extending from the outer side of said portion transversely within said open center and partially thereacross, said outer end portion havinga socket for receiving the swivel Yplate of a drill support rwith the swivel plate lying within said outer end portion, said socket opening laterally toward the open center of said end portion so that the -inner side of the swivel plate is exposed, and a clamp guided for rectilinear movement along said guideway within said open center at the open side of said socket and adjustable outwardly into clamping engagement with the exposed side of said swivel plate.

14. In a drilling apparatus, a support, a frame swivelled on said support to turn relative thereto about an upright axis, said frame having parallel, forwardly extending, vertical side projections supporting parallel horizontal pivot-shafts arranged in vertically spaced relation, an elongated boom frame pivotally mounted at its rear end between said spaced projections on the upper pivot` shaft, said boom frame being swingable horizontally with said swivelled frame about the swivel axis thereof and swingable in vertical planes relative to said swivelled frame, an extensible jack pivotally mounted between said spaced projections on the lower pivot shaft and pivotally connected to said boo-m frame beneath the latter at a point spaced outwardly from the boom frame pivot, said jack upon extension thereof effecting swinging of said boom frame upwardly about its pivot and upon retraction thereof permitting lowering of said boom frame, and a support for a rock drill swivelly mounted at the outer end of said boom frame.

15. In a drilling apparatus, a portable base, frames swivelly mounted on said base to turn horizontally relative thereto about parallel vertical axes spaced equidistantly from the longitudinal vertical center of said base, boom frames pivotally mounted on said swivelled frames respectively to swing in a vertical direction relative thereto and each having at its outer extremity means for supporting a drill, fluid operated means for independently swinging said boom frames in a vertical direction about their pivots, a jack device arranged with its longitudinal axis lying in the central longitudinal vertical plane of said base and engageable with an extraneous abutment for steadying said base during the drilling operation, fluid operated means for extending said jack device, and means for supplying fluid under pressure individually to said fluid operated means including fluid reservoirs, one mounted on said jack device and others mounted one on each of said swivelled frames, and a pump associated with each fluid reservoir, each pump having its intake connected toa reservoir and its discharge connected to a uid operated means.

JOHN C. CURTIS.

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